Fix for heap corruption issue when patch https://codereview.chromium.org/2225243003/ is applied.

runtime/vm/isolate_reload.h

Index: runtime/vm/isolate_reload.h
diff --git a/runtime/vm/isolate_reload.h b/runtime/vm/isolate_reload.h
index 213a9888d044336978fbaacb2eb6078d7fcf366d..ce16bef8b717dc0b519a633abad6e32c95a57d13 100644
--- a/runtime/vm/isolate_reload.h
+++ b/runtime/vm/isolate_reload.h
@@ -117,9 +117,7 @@ class ReasonForCancelling : public ZoneAllocated {
 // Abstract class for also capturing the from_ and to_ class.
 class ClassReasonForCancelling : public ReasonForCancelling {
  public:
-  ClassReasonForCancelling(Zone* zone, const Class& from, const Class& to)
-      : ReasonForCancelling(zone), from_(from), to_(to) { }
-
+  ClassReasonForCancelling(Zone* zone, const Class& from, const Class& to);
   void AppendTo(JSONArray* array);
 
  protected: